PAT1001题解

题目描述：http://pat.zju.edu.cn/contests/pat-a-practise/1001

Java编写，注意格式就好了

import java.util.Scanner;

public class Main {

	public String add(int a, int b){
		String sum = (a + b) + "";
		char[] chars = sum.toCharArray();
		StringBuilder result = new StringBuilder();
		
		if(chars.length > 3){
			
			if(chars[0] == '-'){
				for(int i = 0; i